Heretofore, in the practice of the prior art semiconductor devices have been achieved in crystalline material in which there are linear and planar defects, e.g., dislocations and grain boundaries in the semiconductor region in which separation of electron-hole pairs is achieved. The energy out has been deleteriously altered by the recombination process at recombination centers predominately located in linear and planar defects. It has not been realized heretofore what could be a means of effectively neutralizing this deleterious effect except by procedures which were directly primarily toward the growth of the crystalline material per se.
The prior art impediment to efficient operation of prior semiconductor devices has been especially difficult for solar cell applications. In such solar cell operation, it is the absorption of radiation photons which produces electron-hole pairs. There has not been available technology for improving the output efficiency for current carrying capability of a given semiconductor region with deleterious defects. Consequently, there has been considerable need for advancing the art of semiconductor solar cells for an applicable procedure whereby the deleterious affect arising from the intrinsic characteristics of linear and planar defects, could be obviated, in spite of the presence of the known impediment to the operation of the device.
Although it has been suggested in the prior art that recombination sites could be effectively destroyed since they are due to atoms in the crystal defects, it has not been known how to accomplish a neutralization of the deleterious effects of the recombination centers even though there is continuing presence of the centers in the device.
It is through the practice of the present invention that the difficulties with prior art recited above are obviated. Actually, in certain instances of the practice of the present invention, operational efficiency of crystalline semiconductor solar cells are actually inproved over the efficiency obtainable with the most careful fabrication procedures yet applied for a comparable prior device.